The intracellular phosphorylation of proteins is critical for a plethora of regulatory and signalling mechanisms in eukaryotic cells. Phosphorylation events can govern a wide range of cellular processes, including cell proliferation, differentiation, transcription, and morphology. Serine/threonine protein kinases, also called serine protein kinases, are frequently utilized in signalling cascades as the activity of these enzymes can be finely regulated by stimuli. A common stimulus is phosphorylation of the serine protein kinase itself. Hence, signalling pathways, such as the MAP protein kinase cascade and the JAK/STAT pathway, can contain multiple proteins kinases which are sequentially activated. Ultimately, kinase cascades can result in the phosphorylation of cytoskeletal proteins, transcription factors, and biosynthetic enzymes. Another class of kinases includes the receptor tyrosine kinases. Activated receptor tyrosine kinases not only autophosphorylate, but phosphorylate other intracellular signalling molecules, including those specifically bound to autophosphorylated receptors.
An essential component of the aforementioned signalling pathways is the ability of the cell to desensitize, recycle, and counteract phosphorylation signals. The cell primarily utilizes enzymes, termed phosphatases, which remove the phosphate on tyrosine, serine, and threonine side chains. Dual specificity phosphatases hydrolyze phosphotyrosine, phosphothreonine, and phosphoserine residues (for a review, see, e.g., Fauman and Saper (1996) Trends in Biochem. 21:412). This class of proteins is exemplified by the VH1 or vaccinia virus late H1 gene protein, whose catalytic activity is required for vaccinia virus replication. A human homolog of VH1, VHR, has also been identified. VH1-like dual specificity phosphatase can also include the phosphatases PAC-1 and CL100/MKP-1, hVH-2/MKP-2, hVH-3, MKP-3, MKP-X, MKP-4, hVH-5, and M3/6 proteins. The PAC-1 and CL100 proteins hydrolyze phosphothreonine and phosphotyrosine residues on phosphorylated MAP (mitogen activated protein) kinases. In order to modulate signalling events, the activity and expression of dual specificity phosphatases can be finely regulated. For example, the PAC-1 and CL100 phosphatase can be induced by growth factors (Keyse, S (1995) Biochim. Biophys. Acta1265:152-160).
Thus, the function of dual specificity phosphatase proteins can be critical for the regulation of cellular processes such as proliferation and differentiation. Given the important biological roles and properties of such phosphatases, there exists a need for the identification of novel genes encoding such proteins as well as for the discovery of modulators of such molecules for use in regulating a variety of normal and/or pathological cellular processes.
The present invention is based, in part, on the discovery of a novel dual specificity phosphatase, referred to herein as xe2x80x9c18232xe2x80x9d nucleic acid and protein molecules. The nucleotide sequence of a cDNA encoding 18232 is shown in SEQ ID NO:1, and the amino acid sequence of a 18232 polypeptide is shown in SEQ ID NO:2. In addition, the nucleotide sequence of the coding region is depicted in SEQ ID NO:3.
Accordingly, in one aspect, the invention features a nucleic acid molecule that encodes a 18232 protein or polypeptide, e.g., a biologically active portion of the 18232 protein. In a preferred embodiment, the isolated nucleic acid molecule encodes a polypeptide having the amino acid sequence of SEQ ID NO:2. In other embodiments, the invention provides isolated 18232 nucleic acid molecules having the nucleotide sequence shown in SEQ ID NO:1 or SEQ ID NO:3. In still other embodiments, the invention provides nucleic acid molecules that are substantially identical (e.g., naturally occurring allelic variants) to the nucleotide sequence shown in SEQ ID NO:1 or SEQ ID NO:3. In other embodiments, the invention provides a nucleic acid molecule that hybridizes under stringent hybridization conditions to a nucleic acid molecule comprising the nucleotide sequence of SEQ ID NO:1 or 3, wherein the nucleic acid encodes a full length 18232 protein or an active fragment thereof.
In a related aspect, the invention further provides nucleic acid constructs that include a 18232 nucleic acid molecule described herein. In certain embodiments, the nucleic acid molecules of the invention are operatively linked to native or heterologous regulatory sequences. Also included are vectors and host cells containing the 18232 nucleic acid molecules of the invention, e.g., vectors and host cells suitable for producing 18232 nucleic acid molecules and polypeptides.
In another related aspect, the invention provides nucleic acid fragments suitable as primers or hybridization probes for the detection of 18232-encoding nucleic acids.
In still another related aspect, isolated nucleic acid molecules that are antisense to a 18232 encoding nucleic acid molecule are provided.
In another aspect, the invention features 18232 polypeptides and biologically active or antigenic fragments thereof that are useful, e.g., as reagents or targets in assays applicable to treatment and diagnosis of 18232-mediated or related disorders. In another embodiment, the invention provides 18232 polypeptides having a 18232 activity. Preferred polypeptides are 18232 proteins including at least one dual specificity phosphatase catalytic domain, and, preferably, having a 18232 activity, e.g., a 18232 activity as described herein.
In other embodiments, the invention provides 18232 polypeptides, e.g., a 18232 polypeptide having the amino acid sequence shown in SEQ ID NO:2; an amino acid sequence that is substantially identical to the amino acid sequence shown in SEQ ID NO:2; or an amino acid sequence encoded by a nucleic acid molecule having a nucleotide sequence that hybridizes under stringent hybridization conditions to a nucleic acid molecule comprising the nucleotide sequence of SEQ ID NO:1 or 3, wherein the nucleic acid encodes a full length 18232 protein or an active fragment thereof.
In a related aspect, the invention provides 18232 polypeptides or fragments operatively linked to non-18232 polypeptides to form fusion proteins.
In another aspect, the invention features antibodies and antigen-binding fragments thereof, that react with, or more preferably specifically bind 18232 polypeptides.
In another aspect, the invention provides methods of screening for compounds that modulate the expression or activity of the 18232 polypeptides or nucleic acids.
In still another aspect, the invention provides a process for modulating 18232 polypeptide or nucleic acid expression or activity, e.g. using the screened compounds. In certain embodiments, the methods involve treatment of conditions related to decreased activity or expression of the 18232 polypeptides or nucleic acids, such as conditions involving aberrant cellular proliferation of a 18232 expressing cell, e.g., a hematopoietic cell (e.g., an erythroid cell (e.g., an erythrocyte or an erythroblast), a CD34 positive cell, a glycophorin A-expressing cell, a megakaryocyte). The condition may involve increased hematopoietic cell activity or proliferation as in the case of leukemia, e.g., an erythroleukemia; or decreased hematopoietic cell differentiation as in the case of, e.g., an anemia.
In still another aspect, the invention features a method of modulating (e.g., enhancing or inhibiting) the proliferation, survival, and/or differentiation of a cell, e.g., a 18232-expressing cell, e.g., a hematopoietic cell (e.g., an erythroid cell, a bone marrow cell such as a CD34 positive cell, a megakaryocyte). The method includes contacting the cell with an agent that modulates the activity or expression of a 18232 polypeptide or nucleic acid, in an amount effective to modulate the proliferation and/or differentiation of the cell.
In a preferred embodiment, the 18232 polypeptide has an amino acid sequence identical to, or substantially identical to, SEQ ID NO:2. In other embodiments, the 18232 polypeptide is a fragment of at least 15, 20, 50, 100, 150, or more contiguous amino acids of SEQ ID NO:2.
In a preferred embodiment, the 18232 nucleic acid has a nucleotide sequence identical to, or substantially identical to, SEQ ID NO:1 or 3. In other embodiments, the 18232 nucleic acid is a fragment of at least 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, or more contiguous nucleotides of SEQ ID NO:1 or 3.
In a preferred embodiment, the agent modulates (e.g., increases or decreases) protein phosphatase activity.
In a preferred embodiment, the agent modulates (e.g., increases or decreases) expression of the 18232 nucleic acid by, e.g., modulating transcription, mRNA stability, etc.
In preferred embodiments, the agent is a peptide, a phosphopeptide, a small molecule, e.g., a member of a combinatorial library, or an antibody, or any combination thereof. The antibody can be conjugated to a therapeutic moiety selected from the group consisting of a cytotoxin, a cytotoxic agent and a radioactive metal ion.
In additional preferred embodiments, the agent is an antisense, a ribozyme, or a triple helix molecule, or an 18232 nucleic acid, or any combination thereof.
In a preferred embodiment, the agent is administered in combination with a cytotoxic agent.
In a preferred embodiment, the cell, e.g., the 18232-expressing cell, is a hematopoietic cell, e.g., a myeloid, lymphoid or erythroid cell, or a precursor cell thereof Examples of such cells include myelocytic cells (polymorphonuclear cells), erythrocytic cells, lymphocytes, monocytes, reticular cells, plasma cells and megakaryocytes, as well as stem cells for the different lineages, and precursors for the committed progenitor cells, for example, precursors of blood cells (e.g., red blood cells, such as erythroblasts), macrophages (monoblasts), platelets (megakaryocytes), polymorphonuclear leucocytes (myeloblasts), and lymphocytes (lymphoblasts).
In a preferred embodiment, the cell, e.g., the 18232-expressing cell, is a bone marrow cell, e.g., a bone marrow CD34-expressing cell. Examples of CD34-expressing cells include immature hematopoietic precursor cells, hematopoietic colony-forming cells in bone marrow, including unipotent (CFU-GM, BFU-E) and pluripotent progenitors (CFU-GEMM, CFU-Mix and CFU-blast); as well as stromal cell precursors, terminal deoxynucleotidyl transferase (TdT) expressing B- and T-lymphoid precursors, early myeloid cells and early erythroid cells.
In a preferred embodiment, the cell, e.g., the 18232-expressing cell, is a bone marrow erythroid cell, e.g., an erythroid progenitor (e.g., a glycophorin A expressing cell) or a differentiated cell, e.g., an erythrocyte or a megakaryocyte.
In one embodiment, the hematopoietic cell is a lymphoid cell, e.g., B cells, and their precursors, T cells (e.g., CD4+8+ T cells, CD4+8xe2x88x92 T cells (e.g., helper T cells), CD4xe2x88x92CD8+ T cells (e.g., cytotoxic T cells), CD4xe2x88x928xe2x88x92 T cells, and natural killer T cells) and their precursors.
In a preferred embodiment, the cell, e.g., the 18232-expressing cell, is further contacted with a protein, e.g., a cytokine or a hormone. Exemplary proteins include, but are not limited to, G-CSF, GM-CSF, stem cell factor, interleukin-3 (IL-3), IL-4, Flt-3 ligand, thrombopoietin, and erythropoietin. Most preferably, the protein is erythropoietin. The protein contacting step can occur before, at the same time, or after the agent is contacted. The protein contacting step can be effected in vitro or ex vivo. For example, the cell, e.g., the 18232-expressing cell is obtained from a subject, e.g., a patient, and contacted with the protein ex vivo. The treated cell can be re-introduced into the subject. Alternatively, the protein contacting step can occur in vivo.
In a preferred embodiment, the agent and the 18232-polypeptide or nucleic acid are contacted in vitro or ex vivo.
In a preferred embodiment, the contacting step is effected in vivo in a subject, e.g., as part of a therapeutic or prophylactic protocol. Preferably, the subject is a human, e.g., a patient with an erythroid-associated disorder. For example, the subject can be a patient with an anemia, e.g., hemolytic anemia, aberrant erythropoiesis, secondary anemia in non-hematolic disorders, anemia of chronic disease such as chronic renal failure; endocrine deficiency disease; and/or erythrocytosis (e.g., polycythemia). Alternatively, the subject can be a cancer patient, e.g., a patient with leukemic cancer, e.g., an erythroid leukemia, or a carcinoma, e.g., a renal carcinoma. In other embodiments, the subject is a non-human animal, e.g., an experimental animal.
The contacting step(s) can be repeated.
In a preferred embodiment, the agent decreases the proliferation and/or enhances the differentiation of the cell, e.g., the 18232-expressing cell, e.g., the erythroid cell. Such agents can be used to treat or prevent cancers, e.g., leukemic cancers such as erythroid leukemias, or carcinomas, e.g., renal or lung carcinomas.
In a preferred embodiment, the agent increases the number of erythroid cells, by e.g., increasing the proliferation, survival, and/or stimulating the differentiation, of erythroid progenitor cells. Such agents can be used to treat or prevent anemias, e.g., hemolytic anemias, aberrant erythropoiesis, secondary anemias in non-hematolic disorders, anemias of chronic diseases such as chronic renal failure; endocrine deficiency diseases; and/or erythrocytosis (e.g., polycythemias).
In a preferred embodiment, the agent increases the number of erythroid cells, by e.g., increasing the proliferation, survival, and/or stimulating the differentiation, of granulocytic and monocytic progenitor cells, e.g., CFU-GM, CFU-G (colony forming unitxe2x80x94granulocyte), myeloblast, promyelocyte, myelocyte, a metamyelocyte, or a band cell. Such compounds can be used to treat or prevent neutropenia and granulocytopenia, e.g., conditions caused by cytotoxic chemotherapy, AIDS, congenital and cyclic neutropenia, myelodysplastic syndromes, or aplastic anemia.
In another aspect, the invention features a method of modulating hematopoiesis, e.g., erythropoiesis, comprising contacting a hematopoietic cell, e.g., a blood cell, such as an erythroid cell, with a agent that increases or decreases the activity or expression of a 18232 polypeptide or nucleic acid, thereby modulating the differentiation of the hematopoietic cell, e.g., the blood cell.
In a preferred embodiment, the 18232 polypeptide has an amino acid sequence identical to, or substantially identical to, SEQ ID NO:2. In other embodiments, the 18232 polypeptide is a fragment of at least 15, 20, 50, 100, 150, or more contiguous amino acids of SEQ ID NO:2.
In a preferred embodiment, the 18232 nucleic acid has a nucleotide sequence identical to, or substantially identical to, SEQ ID NO:1 or 3. In other embodiments, the 18232 nucleic acid is a fragment of at least 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, or more contiguous nucleotides of SEQ ID NO:1 or 3.
In a preferred embodiment, the agent modulates (e.g., increases or decreases) protein phosphatase activity.
In preferred embodiments, the agent is a peptide, a phosphopeptide, a small molecule, e.g., a member of a combinatorial library, or an antibody, or any combination thereof. The antibody can be conjugated to a therapeutic moiety selected from the group consisting of a cytotoxin, a cytotoxic agent and a radioactive metal ion.
In additional preferred embodiments, the agent is an antisense, a ribozyme, or a triple helix molecule, or an 18232 nucleic acid, or any combination thereof.
In a preferred embodiment, the agent is administered in combination with a cytotoxic agent.
In a preferred embodiment, the hematopoietic cell is an erythroid cell, e.g., an erythroid progenitor or differentiated cell, e.g., an erythrocyte or a megakaryocyte.
In a preferred embodiment, the hematopoietic cell is a bone marrow CD34-expressing cell.
In a preferred embodiment, the agent and the 18232-polypeptide or nucleic acid are contacted in vitro or ex vivo.
In a preferred embodiment, the contacting step is effected in vivo in a subject, e.g., as part of a therapeutic or prophylactic protocol. Preferably, the subject is a human, e.g., a patient with a hematopoietic disorder such as an erythroid-associated disorder. For example, the subject can be a patient with an anemia, e.g., a drug-induced anemia (e.g., a chemotherapy-induced anemia), hemolytic anemia, aberrant erythropoiesis, secondary anemia in non-hematolic disorders, anemia of chronic disease such as chronic renal failure; endocrine deficiency disease; and/or erythrocytosis (e.g., polycythemia). Preferably, the erythroid-associated disorder is a drug-induced anemia (e.g., a chemotherapy induced anemia). Alternatively, the subject can be a cancer patient, e.g., a patient with leukemic cancer, e.g., an erythroid leukemia. In other embodiments, the subject is a non-human animal, e.g., an experimental animal.
In a preferred embodiment, the method further includes contacting of the erythroid cell with a protein, e.g., a hormone. The protein can be a member of the following non-limiting group: G-CSF, GM-CSF, stem cell factor, interleukin-3 (IL-3), IL-4, Flt-3 ligand, thrombopoietin, and erythropoietin. More preferably, the protein is erythropoietin. The protein contacting step can occur before, at the same time, or after the agent is contacted. The protein contacting step can be effected in vitro or ex vivo. For example, the cell, e.g., the erythroid cell can be obtained from a subject, e.g., a patient, and contacted with the protein ex vivo. The treated cell can be re-introduced into the subject. Alternatively, the protein contacting step can occur in vivo.
The contacting step(s) can be repeated.
In a preferred embodiment, the agent increases the number of hematopoietic cells, e.g., erythroid cells, by e.g., increasing the proliferation, survival, and/or stimulating the differentiation, of hematopoietic (e.g., erythroid) progenitor cells, in the subject. Such agents can be used to treat an anemia, e.g., a drug-(e.g., chemotherapy-) induced anemia, hemolytic anemia, aberrant erythropoiesis, secondary anemia in non-hematolic disorder, anemia of chronic diseases such as chronic renal failure; endocrine deficiency disease; and/or erythrocytosis (e.g., polycythemias).
In a preferred embodiment, the agent increases the number of erythroid cells, by e.g., increasing the proliferation, survival, and/or stimulating the differentiation, of granulocytic and monocytic progenitor cells, e.g., CFU-GM, CFU-G (colony forming unitxe2x80x94granulocyte), myeloblast, promyelocyte, myelocyte, a metamyelocyte, or a band cell. Such compounds can be used to treat or prevent neutropenia and granulocytopenia, e.g., conditions caused by cytotoxic chemotherapy, AIDS, congenital and cyclic neutropenia, myelodysplastic syndromes, or aplastic anemia.
In yet another aspect, the invention features a method of treating or preventing a hematopoietic disorder, e.g., an erythroid-associated disorder, in a subject. The method includes administering to the subject an effective amount of an agent that modulates the activity or expression of a 18232 polypeptide or nucleic acid such that the hematopoietic disorder is ameliorated or prevented.
In a preferred embodiment, the 18232 polypeptide has an amino acid sequence identical to, or substantially identical to, SEQ ID NO:2. In other embodiments, the 18232 polypeptide is a fragment of at least 15, 20, 50, 100, 150, or more contiguous amino acids of SEQ ID NO:2.
In a preferred embodiment, the 18232 nucleic acid has a nucleotide sequence identical to, or substantially identical to, SEQ ID NO:1 or 3. In other embodiments, the 18232 nucleic acid is a fragment of at least 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, or more contiguous nucleotides of SEQ ID NO:1 or 3.
In a preferred embodiment, the agent modulates (e.g., increases or decreases) protein phosphatase activity.
In a preferred embodiment, the agent modulates (e.g., increases or decreases) expression of the 18232 nucleic acid by, e.g., modulating transcription, mRNA stability, etc.
In preferred embodiments, the agent is a peptide, a phosphopeptide, a small molecule, e.g., a member of a combinatorial library, or an antibody, or any combination thereof. The antibody can be conjugated to a therapeutic moiety selected from the group consisting of a cytotoxin, a cytotoxic agent and a radioactive metal ion.
In additional preferred embodiments, the agent is an antisense, a ribozyme, or a triple helix molecule, or an 18232 nucleic acid, or any combination thereof.
In a preferred embodiment, the agent is administered in combination with a cytotoxic agent.
In a preferred embodiment, the subject is a human, e.g., a patient with a hematopoietic disorder, e.g., an erythroid-associated disorder. For example, the subject can be a patient with an anemia, e.g., a drug-(chemotherapy-) induced anemia, hemolytic anemia, aberrant erythropoiesis, secondary anemia in non-hematolic disorders, anemia of chronic disease such as chronic renal failure; endocrine deficiency disease; and/or erythrocytosis (e.g., polycythemia). Preferably, the anemia is a drug-(chemotherapy-) induced anemia. Alternatively, the subject can be a cancer patient, e.g., a patient with leukemic cancer, e.g., an erythroid leukemia, or a patient with a carcinoma, e.g., a renal carcinoma. In other embodiments, the subject is a non-human animal, e.g., an experimental animal.
In a preferred embodiment, the agent decreases the proliferation and/or enhances the differentiation of a cell, e.g., a 18232-expressing cell, e.g., a hematopoietic cell (e.g., an erythroid cell), in the subject. Such agents can be used to treat or prevent cancers, e.g., leukemic cancers such as erythroid leukemias, or carcinomas, e.g., renal carcinomas.
In a preferred embodiment, the agent increases the number of hematopoietic cells, e.g., blood cells (e.g., erythroid cells), by e.g., increasing the proliferation, and/or stimulating the differentiation, of erythroid progenitor cells, in the subject. Such agents can be used to treat an anemia, e.g., a drug-(chemotherapy-) induced anemia, a hemolytic anemia, aberrant erythropoiesis, a secondary anemia in non-hematolic disorder, anemia of chronic diseases such as chronic renal failure; endocrine deficiency disease; and/or erythrocytosis (e.g., polycythemias).
In a preferred embodiment, the agent increases the number of erythroid cells, by e.g., increasing the proliferation, survival, and/or stimulating the differentiation, of granulocytic and monocytic progenitor cells, e.g., CFU-GM, CFU-G (colony forming unitxe2x80x94granulocyte), myeloblast, promyelocyte, myelocyte, a metamyelocyte, or a band cell. Such compounds can be used to treat or prevent neutropenia and granulocytopenia, e.g., conditions caused by cytotoxic chemotherapy, AIDS, congenital and cyclic neutropenia, myelodysplastic syndromes, or aplastic anemia.
In a preferred embodiment, the disorder is a hematopoietic disorder, e.g. an erythroid-associated disorder. Examples of erythroid-associated disorder include drug-(chemotherapy-) induced anemia, hemolytic anemia, aberrant erythropoiesis, secondary anemia in non-hematolic disorders, anemia of chronic disease such as chronic renal failure; endocrine deficiency disease; and/or erythrocytosis (e.g., polycythemia). Preferably, the erythroid associated disorder is a drug-(chemotherapy-) induced anemia.
In a preferred embodiment, the disorder is a cancer, e.g., a leukemic cancer, e.g., an erythroid leukemia, or a carcinoma, e.g., a renal carcinoma.
In a preferred embodiment, the method further includes administering an effective amount of a protein, e.g., a cytokine or a hormone, to the subject. Exemplary proteins include, but are not limited to, G-CSF, GM-CSF, stem cell factor, interleukin-3 (IL-3), IL-4, Flt-3 ligand, thrombopoietin, and erythropoietin. Preferably, the protein is erythropoietin. The protein can be administered before, at the same time or after, administration of the agent.
The administration of the agent and/or protein can be repeated.
In still another aspect, the invention features a method for evaluating the efficacy of a treatment of a disorder, in a subject. The method includes treating a subject with a protocol under evaluation; assessing the expression of a 18232 nucleic acid or 18232 polypeptide, such that a change in the level of 18232 nucleic acid or 18232 polypeptide after treatment, relative to the level before treatment, is indicative of the efficacy of the treatment of the disorder.
In a preferred embodiment, the disorder is a hematopoietic disorder, e.g., an erythroid-associated disorder. Examples of erythroid-associated disorders include an anemia, e.g., a drug-(e.g., chemotherapy-) induced anemia, a hemolytic anemia, aberrant erythropoiesis, secondary anemia in non-hematolic disorder, anemias of chronic disease such as chronic renal failure; endocrine deficiency diseases; and/or erythrocytosis (e.g., polycythemia).
In a preferred embodiment, the disorder is a cancer, e.g., leukemic cancer, e.g., an erythroid leukemia, or a carcinoma, e.g., a renal carcinoma.
In a preferred embodiment, the subject is a human.
In a preferred embodiment, the subject is an experimental animal, e.g., an animal model for a hematopoietic-(e.g., an erythroid-) associated disorder.
In a preferred embodiment, the method can further include treating the subject with a protein, e.g., a cytokine or a hormone. Exemplary proteins include, but are not limited to, G-CSF, GM-CSF, stem cell factor, interleukin-3 (IL-3), IL-4, Flt-3 ligand, thrombopoietin, and erythropoietin. Preferably, the protein is erythropoietin.
The invention also features a method of diagnosing a disorder, e.g., hematopoietic disorder (e.g., an erythroid-associated disorder), in a subject. The method includes evaluating the expression or activity of a 18232 nucleic acid or a 18232 polypeptide, such that, a difference in the level of 18232 nucleic acid or 18232 polypeptide relative to a normal subject or a cohort of normal subjects is indicative of the disorder.
In a preferred embodiment, the subject is a human.
In a preferred embodiment, the evaluating step occurs in vitro or ex vivo. For example, a sample, e.g., a blood sample, is obtained from the subject.
In a preferred embodiment, the evaluating step occurs in vivo. For example, by administering to the subject a detectably labeled agent that interacts with the 18232 nucleic acid or polypeptide, such that a signal is generated relative to the level of activity or expression of the 18232 nucleic acid or polypeptide.
In a preferred embodiment, the disorder is a hematopoietic disorder, e.g., a hematopoietic disorder as described herein.
In a preferred embodiment, the disorder is an erythroid-associated disorder, e.g., an erythroid-associated disorder as described herein.
The invention also provides assays for determining the activity of or the presence or absence of 18232 polypeptides or nucleic acid molecules in a biological sample, including for disease diagnosis.
In further aspect, the invention provides assays for determining the presence or absence of a genetic alteration in a 18232 polypeptide or nucleic acid molecule, including for disease diagnosis.
In yet another aspect, the invention features a method for identifying an agent, e.g., a compound, which modulates the activity of a 18232 polypeptide, e.g., a 18232 polypeptide as described herein, or the expression of a 18232 nucleic acid, e.g., a 18232 nucleic acid as described herein, including contacting the 18232 polypeptide or nucleic acid with a test agent (e.g., a test compound); and determining the effect of the test compound on the activity of the polypeptide or nucleic acid to thereby identify a compound which modulates the activity of the polypeptide or nucleic acid.
In a preferred embodiment, the activity of the 18232 polypeptide is a protein phosphatase activity.
In a preferred embodiment, the activity of the 18232 polypeptide is hematopoiesis, e.g., erythropoiesis.
In a preferred embodiment, the activity of the 18232 polypeptide is proliferation, differentiation, and/or survival of a cell, e.g., a 18232-expressing cell, e.g., a hematopoietic cell (e.g., a bone marrow cell such as a CD34 positive cell, an erythroid cell, a megakaryocyte).
In preferred embodiments, the agent is a peptide, a phosphopeptide, a small molecule, e.g., a member of a combinatorial library, or an antibody, or any combination thereof.
In additional preferred embodiments, the agent is an antisense, a ribozyme, or a triple helix molecule, or an 18232 nucleic acid, or any combination thereof.
Other features and advantages of the invention will be apparent from the following detailed description, and from the claims.